Various parts of an aircraft, such as the wings, are made of hollow cavities. The cavities may house cables that provide power, communication, and/or fuel for the aircraft. Additionally, a cavity may have one or more drainage holes in its floor to drain water or fuel that may have leaked in the cavity. These drainage holes enhance aircraft safety by preventing the accumulation of fluid and weight in the wings of the aircraft. However, a drainage hole may potentially expose critical cables in an aircraft cavity to an external hazard, such as fire flames from a nearby jet engine.